Drivetrain assembly and method for simultaneous sweeping and tapping motions in oral cleaning devices with a double actuating mechanism

Abstract

A drivetrain assembly for an oral cleaning device is disclosed, comprising a first actuator assembly with a U-shaped structural component having a pair of arms with coils, a resonator with a magnet positioned adjacent to the coil ends, and a coupling spring connected to the magnet and a brush head shaft. The coupling spring transmits generated motion to a brush head member. A second actuator assembly includes a second U-shaped structural component with a second pair of arms and coils, and a second resonator with a magnet directly connected to the brush head shaft. A controller generates and transmits driving signals to the coils, interacting with the magnets to produce simultaneous movement patterns, such as rotation or axial motion, of the brush head. This configuration enhances cleaning efficiency and adaptability in oral hygiene devices.

Description

2025PF00381DRIVETRAIN ASSEMBLY AND METHOD FOR SIMULTANEOUS SWEEPING AND TAPPING MOTIONS IN ORAL CLEANING DEVICES WITH A DOUBLE ACTUATING MECHANISMField of the Disclosure

[0001] The present disclosure relates generally to personal care devices, such as power toothbrush devices, and more specifically to drivetrain assemblies for power toothbrushes, and more particularly to systems and methods for improving cleaning performance by generating simultaneous sweeping and tapping motions with a double actuating mechanism.Background

[0002] Current modern power toothbrush devices use rotary motion about a central axis of the brush head. This motion is known as a sweeping motion. A simplified schematic representation of a modern power toothbrush is shown in FIG. 1. As shown in FIG. 1, power toothbrush 10 has a handle 12 and a brush head 14. Bristles 16 are shown extending from brush head 14. In use, brush head 14 is driven by a drive system contained within handle 12. The bristles are typically rotated by the drive system about central axis A in a sweeping motion SM. The sweeping motion is typically embodied as movement that is linear, rotational, or a combination of both linear and rotational and the movement is tangential to the direction that the bristles are facing.

[0003] Unfortunately, toothbrush devices that employ the sweeping motion alone are not optimized for all target areas in the mouth (e.g., interproximal areas, gumline areas, incisor surfaces, molar surfaces, and overall surface areas of the teeth). Achieving proper cleaning performance at all target areas depends on a number of factors, including toothbrush layout, motion of the toothbrush, and user handling. Although manufacturers can control toothbrush layout or design, it is challenging to design a toothbrush that performs optimally at all target areas due to conflicting requirements for the different areas. Consequently, toothbrushes can have non-optimal performance at certain areas of interest. Although consumers could ideally use different types of toothbrushes to achieve the best cleaning in all the target areas, consumers only employ a single toothbrush device for daily oral care routines.2025PF00381

[0004] While certain systems and methods utilize a single actuator to generate different types of motions for different areas in the mouth, such configurations can be limited in the range of motion provided to the brush head. Additionally, single actuator systems can also exhibit inefficiencies in delivering secondary motions to the brush head, resulting in reduced performance and suboptimal cleaning outcomes.

[0005] Thus, there is a need in the art for improved power toothbrush devices and systems and methods that achieve stain and / or plaque removal and gum health objectives using simultaneous actuation of the sweeping and tapping motions with an additional actuator that is directly connected to the brush head shaft.Summary of the Disclosure

[0006] The present disclosure is directed generally to inventive electric or powered personal care devices, such as, an electric toothbrush or shaver, and methods for producing high performance cleansing results using the electric or powered personal care devices. The inventive systems achieve improved stain and / or plaque removal and gum health objectives by precisely and controllably generating a sweeping motion in combination with a tapping motion with separate actuators. The aforementioned limitations can be overcome by combining the sweeping motion with a vertical up and down periodic motion that can be generated and driven with a suitable drivetrain. While two separate mechanical systems can be coupled together to drive the tapping and sweeping motions, such a combination can come with drawbacks of cost, size, complexity, and inefficiencies that prohibit competitiveness in the power toothbrush market. Various embodiments and implementations herein are directed to improved systems having a brush head member, a set of bristles, and a drivetrain assembly that achieves both the sweeping and tapping motions without compromising on other qualities, such as, cost, size, complexity, efficiency, or user experience. The drivetrain assembly allows freedom of rotation about the central axis and motion in the vertical direction parallel to the direction of the bristles or an axis of alignment of the bristles and also independently drives these motions. Thus, the improved drivetrain assembly simultaneously generates (i) periodic movement about a central axis of the device or along a line that is tangential to the brush head member; and (ii) periodic linear movement in a direction that is parallel to a z-axis of the device or an axis of alignment of the bristles. Applicant has recognized2025PF00381and appreciated that electric or powered personal care devices can be significantly improved upon by controllably moving the bristles in a sweeping motion and controllably driving the bristles in a direction that is parallel to the z-axis of the device or an axis of alignment of the bristles (i.e., in a tapping motion), where the movement is within a particular range of critical amplitudes and frequencies. Additionally, Applicant has recognized and appreciated that the original rotational motion can be transmitted to the brush head shaft via a coupling spring, and the periodic linear motion can be directly transmitted to the brush head shaft via another actuator, thereby advancing the efficacy of oral cleaning devices beyond the capabilities of systems and methods that rely on a single actuator for generating different types of motions for different areas in the mouth.

[0007] In a first aspect, a drivetrain assembly of an oral cleaning device is provided. The drive train assembly includes a first actuator assembly comprising a first U-shaped core having a first pair of arms with a first pair of coils, a first resonator with a first magnet positioned adjacent free ends of the first pair of coils, and a coupling spring connected to the first magnet and a brush head shaft. The coupling spring transmits a first generated motion to a brush head member of the oral cleaning device. A second actuator assembly is also included, comprising a second U-shaped core having a second pair of arms with a second pair of coils, and a second resonator with a second magnet positioned adjacent free ends of the second pair of coils. The second resonator and the second magnet are directly connected to the brush head shaft. A controller is also included that is configured to generate and transmit to the first pair of coils first driving signals that interact with north and south poles of the first magnet to generate a first movement pattern comprising the first generated motion. It is additionally configured to generate and transmit to the second pair of coils second driving signals that interact with north and south poles of the second magnet to generate a second movement pattern simultaneously as the first movement pattern.

[0008] According to an embodiment, the first U-shaped core is integral with the second U-shaped core.

[0009] According to an embodiment, each coil of the first pair of coils is wrapped around an arm of the first pair of arms, and each coil extends parallel to a central ais of the oral cleaning device. The free ends of the first pair of coils are directed away from the brush head member.2025PF00381

[0010] According to an embodiment, each coil of the second pair of coils is wrapped around an arm of the second pair of arms and each coil extends parallel to a central axis of the oral cleaning device. The free ends of the second pair of coils are directed toward the brush head member.

[0011] According to an embodiment, the coupling spring extends parallel to a central axis of the oral cleaning device alongside the first and second U-shaped cores.

[0012] According to an embodiment, the controller is configured to generate and transmit to the second pair of coils third driving signals that interact with the north and south poles of the second magnet to generate the first movement pattern.

[0013] According to an embodiment, the third driving signals are transmitted simultaneously as the first driving signals.

[0014] According to an embodiment, the controller is configured to generate and transmit the first driving signals set to a first frequency, and at the same time generate and transmit the third driving signals set to a second frequency, different than the first frequency.

[0015] According to an embodiment, the first movement pattern comprises rotating the first magnet and the brush head member about a central axis of the oral cleaning device.

[0016] In accordance with an embodiment, the second movement pattern is the same as the first movement pattern.

[0017] In accordance with an embodiment, the second movement pattern comprises moving the second magnet and the brush head member along another axis of the oral cleaning device.

[0018] In accordance with an embodiment, the another axis is substantially parallel to an axis of alignment of bristles of the brush head member.

[0019] In a second aspect, an oral cleaning device is provided. The oral cleaning device includes a body portion, a brush head member removably coupled to the body portion and comprising a set of cleaning bristles, and a drivetrain assembly within the body portion. The drivetrain assembly comprises a first actuator assembly, comprising a first U-shaped core having a first pair of arms with a first pair of coils, a first resonator with a first magnet positioned adjacent free ends of the first pair of coils, and a coupling spring connected to the first magnet and a brush head shaft. The coupling spring transmits a first generated motion to a brush head member of the oral cleaning device. The drivetrain assembly also includes a second actuator assembly,2025PF00381comprising a second U-shaped core having a second pair of arms with a second pair of coils, and a second resonator with a second magnet positioned adjacent free ends of the second pair of coils. The second resonator and the second magnet are directly connected to the brush head shaft. A controller is also included that is configured to generate and transmit first driving signals to the first pair of coils that interact with north and south poles of the first magnet to generate a first movement pattern comprising the first generated motion, and generate and transmit second driving signals to the second pair of coils that interact with north and south poles of the second magnet to generate a second movement pattern simultaneously as the first movement pattern.

[0020] According to an embodiment, the first U-shaped core is integral with the second U-shaped core.

[0021] According to an embodiment, the first movement pattern comprises rotating the first magnet and the brush head member about a central axis of the oral cleaning device. The second movement pattern is the same as the first movement pattern or the second movement pattern comprises moving the second magnet and the brush head member along another axis of the oral cleaning device.

[0022] In various implementations, a processor or controller may be associated with one or more storage media (generically referred to herein as “memory,” e.g., volatile, and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM, floppy disks, compact disks, optical disks, magnetic tape, etc.). In some implementations, the storage media may be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform at least some of the functions discussed herein. Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or controller so as to implement various aspects as discussed herein. The terms “program” or “computer program” are used herein in a generic sense to refer to any type of computer code (e.g., software or microcode) that can be employed to program one or more processors or controllers.

[0023] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as2025PF00381being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.

[0024] These and other aspects of the various embodiments will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.Brief Description of the Drawings

[0025] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the various embodiments.

[0026] FIG. 1 is a simplified schematic representation of an end view of a modern power toothbrush device configured to employ a sweeping motion, according to aspects of the present disclosure.

[0027] FIG. 2 is a simplified schematic representation of a portion of a power toothbrush device, according to aspects of the present disclosure.

[0028] FIG. 3 is a simplified schematic representation of an end view of a power toothbrush device configured to employ sweeping and tapping motions, according to aspects of the present disclosure.

[0029] FIG. 4 is a schematic representation of a power toothbrush device, according to aspects of the present disclosure.

[0030] FIG. 5 is another schematic representation of a power toothbrush device, according to aspects of the present disclosure.

[0031] FIG. 6A is a schematic representation of a portion of a drivetrain assembly of a power toothbrush device, according to aspects of the present disclosure.

[0032] FIG. 6B is a schematic representation of a portion of a drivetrain assembly of a power toothbrush device, according to aspects of the present disclosure.2025PF00381

[0033] FIG. 6C is a schematic representation of the brush head driving actuator performing a sweeping motion, according to aspects of the present disclosure.

[0034] FIG. 6D is a schematic representation of the brush head driving actuator performing a tapping motion, according to aspects of the present disclosure.

[0035] FIG. 7A depicts an exemplary schematic representation of the coils wrapped around the arms of the U-shaped core of the drivetrain assembly, according to aspects of the present disclosure.

[0036] FIG. 7B is a schematic representation of example driving voltages applied by individual electronic drivers to the coils of FIG. 7A, according to aspects of the present disclosure.

[0037] FIG. 8 is a diagrammatic representation of example driving voltages applied to each coil at distinct frequencies for generating the sweeping and tapping motions simultaneously, according to aspects of the present disclosure.

[0038] FIG. 9 is a schematic representation of an example dual arbitrary waveform generator driving two coils of the drivetrain assembly, according to aspects of the present disclosure.

[0039] FIG. 10 is a schematic representation of an example coil driving circuit for generating sweeping and tapping motions in a drivetrain assembly, according to aspects of the present disclosure.

[0040] FIG. 11 is a schematic representation of an H-shaped double actuator enabling simultaneous sweeping and tapping motions for a drivetrain assembly of an oral cleaning device, according to aspects of the present disclosure.Detailed Description of Embodiments

[0041] The present disclosure describes various embodiments of improved systems and methods for driving brush heads of electric or powered personal care devices, such as electric toothbrushes or shavers and the like. Applicant has recognized and appreciated that personal care devices can provide improved cleansing performance at critical areas of the user’s mouth by driving the bristles of the toothbrush in a vertical motion that is parallel to the direction of the bristles, in addition to movement about a central axis of the device or along a line that is tangential to the brush head member. As used herein, the term “vertical” does not mean an absolute direction with respect to the ground but instead is used to indicate a relative direction of movement2025PF00381illustrated in the Figures. As described herein, the inventive tapping motion within power toothbrush devices: (i) achieves deeper reach in gum pockets to remove subgingival plaque, (ii) achieves higher peak forces at surfaces which improve plaque and / or stain removal, (iii) prevents pinning of bristle tufts which improves plaque removal by restoring beneficial tuft sweeping behavior, (iv) achieves more resilience to variables of use like toothbrush placement, toothbrush angle, and toothbrush pressure, and (v) provides new options for experiential modes for the consumer. Additionally, improved cleansing performance can be realized by transmitting the tapping motion to the brush head member using a separate actuator, distinct from the actuator used to generate and transmit the rotational motion. Accordingly, exemplary improved systems and methods described or otherwise envisioned herein provide a brush head member having a set of bristles and a drivetrain assembly to generate rotational and linear movements alone or simultaneously using dual actuators. The periodic linear movement is transmitted directly to a brush head shaft to move the bristles in a direction that is parallel to the z-axis of the device. Applicant has recognized and appreciated that such controlled linear movement can be combined with rotational movement to provide improved cleaning performance.

[0042] A particular goal of utilization of the embodiments and implementations herein is to provide a mechanism to provide a combined sweeping and tapping motion in a power toothbrush device like, e.g., a Philips Sonicare™ electric toothbrush (manufactured by Koninklijke Philips N.V.). However, the components of the device may be utilized with many other personal care devices, including oral care devices, oral cleaning devices, flossers, skin cleaners, and many other devices. This disclosure should not be limited by the specific embodiments depicted and described.

[0043] Power toothbrushes (PTBs) are electrically driven toothbrushes. The drivetrain in power toothbrushes often includes a double-resonant mechanism consisting of two moving bodies and their connected springs to help the generated motion such that less power is required and to minimize vibrations of the product. The double-resonant mechanism is driven via two coils having a U-shape metal core. When electrical signals pass through the coils, a magnetic field is generated that either attracts or repels a permanent magnet creating a torque to make the permanent magnet rotate. When one coil attracts the magnet, and the other coil repels the magnet, a rotational motion is generated. When both coils either attract or repel, the magnet makes a vertical translational motion.2025PF00381

[0044] FIG. 2 shows a simplified schematic representation of a portion of a power toothbrush device 100 configured to generate a sweeping motion and / or a tapping motion. Power toothbrush device 100 includes brush head 114 and bristles 116 which can be driven to rotate about central axis A and pulse or tap in direction RD2. The directions provided in FIG. 2 are included to demonstrate the spatial terminology used in the art and the present application. As used herein, the term “vertical” means the direction indicated. Axial direction AD is parallel to central axis A and extends along a y-axis of the device 100. Radial direction RD 1 is orthogonal to central axis A and radial direction RD2 and extends along an x-axis of the device 100. Radial direction RD2 is orthogonal to both axial direction AD and radial direction RD1, parallel to the axes of the bristles 116 depicted, and extends along a z-axis of the device 100. The tapping motion described herein refers to controllable movement of the brush head and / or bristles in radial direction RD2. In other words, the tapping motion refers to motion of the bristles that is parallel to an axis of alignment of the bristles or normal (i.e., perpendicular) to the brush head member. The sweeping motion refers to rotary and / or linear motion of the bristles that is perpendicular to the axis of alignment of the bristles. In embodiments, the tapping motion refers to controllable movement of the brush head and / or bristles in radial direction RD2 by rotating the brush head shaft about an axis extending in radial direction RD1 (i.e., about an x-axis of the device).

[0045] Referring to FIG. 3, a schematic representation of an end view of power toothbrush device 100 is provided. Device 100 is configured to generate a variety of motions, each motion comprising a summation (i.e., a cumulative act, motion, or effect) of sweeps or strokes and pulses or taps. The sweeps or strokes are directed in direction SM, (which would be in a direction between occlusal surfaces (i.e., biting surfaces) and the gumline when the toothbrush is held with the bristle tips pointing toward a buccal side of the teeth). The pulses or taps are directed in the vertical direction TM (which would be a lingual to facial direction when the toothbrush is held with the bristle tips pointing toward a buccal side of the teeth). As discussed in greater detail herein, the power toothbrush device 100 can be configured to turn on and off the sweeping and tapping motions (SM and TM) for optimizing motion to a specific region that a particular motion is most beneficial for. In some cases, the particular motion comprises either the sweeping motion alone or the tapping motion alone. In other cases, the particular motion comprises some combination of the sweeping motion and the tapping motion. For example, in embodiments, the tapping motion alone can be used for the lower lingual anterior region of the mouth or to better reach at interproximal2025PF00381regions in-between teeth. The tapping motion can be used with the sweeping motion for the buccal anterior region of the mouth. Alternatively, the sweeping motion alone can be used for the buccal anterior region of the mouth.

[0046] The tapping motion improves the performance of the sweeping motion, in part, by untrapping or unpinning the bristle tufts. Bristle trapping or pinning is a phenomena where, under heavy loads, the bristles can become constrained or trapped such that they no longer freely move according to the sweeping motion delivered by the drivetrain. When the user applies too much load when brushing, the bristle tufts can become partially constrained in their movement on the surface of the teeth. As a result of the constraint, the sweeping motion is reduced, and the cleaning performance can suffer. When the user applies even more load, the bristle tufts can become trapped or pinned where the tufts do not move at all when brushing. As a result of the trapped or pinned bristles, there is no sweeping motion, and the user derives no benefit from the sweeping motion from the drivetrain assembly. When bristles are constrained or trapped, the cleaning benefits only resume when the user manually moves the product to a new orientation and frees the bristles from the heavy loads.

[0047] The sweeping motion performs best when the bristles touch the surface of the tooth and can move freely along large surface areas without being constrained. When brushing with sweeping and tapping motions together, the bristle tufts splay out as the load increases or as the brush head moves in direction DR1 due to the drivetrain assembly generating the vertical up-down movement (i.e., the tapping motion). As the load increases due to the force exerted from the drivetrain assembly or otherwise due to user applied load for example, the tufts can become more and more constrained. However, if the amplitude of the brush head movement in direction DR1 is large enough, the large amplitude movement can cause buckling of a constrained or trapped bristle and effectively release or unload the bristle. Thus, the addition of the tapping motion to the sweeping motion allows the bristles to move with more freedom, thereby improving cleaning performance.

[0048] Critically, when the brush head moves in direction DR2 during the tapping motion, the behavior reverses and as the load decreases further, the tufts become less and less constrained. The tapping motion can allow the tufts to cover a larger surface area during the sweeping motion and improves plaque removal by restoring the beneficial sweeping motion.2025PF00381

[0049] The addition of the tapping motion to the sweeping motion also achieves a deeper reach into gum pockets to remove subgingival plaque. Within gum pockets, the addition of the tapping motion achieves improved cleaning performance on marginal areas, interproximal areas, mesial areas, and buccal areas, and an improved overall cleaning performance. In example embodiments, the deeper reach and improved cleaning performance is achieved under a 30 degree roll angle, a 45 degree roll angle, or a 60 degree roll angle, or any suitable roll angle. Thus, the addition of the tapping motion renders the cleaning efficiency of the brush to be more robust to user orientation, and less dependent on the user’s technique, than using the sweeping motion alone.

[0050] The improved cleaning performance can be achieved by using critical operating parameters for the tapping motion discussed herein. While a variety of drivetrain assemblies can be implemented to generate the tapping motion, we will discuss several exemplary assemblies below to illustrate how the invention can be implemented and practiced.

[0051] Referring to FIG. 4, a schematic representation of the power toothbrush device 100 is shown. A head member 104, brush head 114, and / or bristle face 115 are mounted so as to be able to move relative to the body portion housing 102. The movement can be any of a variety of different movements, including vibrations or rotation, among others. According to one embodiment, head member 104 is mounted to the body portion housing 102 so as to be able to vibrate relative to body portion housing 102, or, as another example, brush head 114 is mounted to head member 104 so as to be able to vibrate relative to body portion housing 102, or, as another example, bristle face 115 is mounted to head member 104 so as to be able to vibrate relative to body portion housing 102. The head member 104 can be fixedly mounted onto body portion housing 102, or it may alternatively be detachably mounted so that head member 104 can be replaced with a new one when the bristles or another component of the device are worn out and require replacement.

[0052] Referring to FIG. 5, the body portion 102 can include a drivetrain assembly 122 with an actuator or motor for generating movement and a resonator 120 configured to transmit the generated movements to head member 104. For example, drivetrain assembly 122 comprises a motor or electromagnet(s) that generates movement of brush head shaft 124, which is subsequently transmitted to the head member 104. Drivetrain assembly 122 can include components such as a power supply, an oscillator, and one or more electromagnets, among other components. In this2025PF00381embodiment the power supply comprises one or more rechargeable batteries 126 (see FIG. 4) which can, for example, be electrically charged in a charging holder in which power toothbrush device 100 is placed when not in use (not shown).

[0053] Still referring to FIG. 5, the body portion 102 of the device 100 also comprises a controller 130. Controller 130 may be formed of one or multiple modules and is configured to operate the power toothbrush device 100 in response to an input, such as input obtained via user input or an input from a sensor within the device. Controller 130 can comprise, for example, a processor 132 and a memory 134, and can optionally include a connectivity module 138. The processor 132 may take any suitable form, including but not limited to a microcontroller, multiple microcontrollers, circuitry, a single processor, or plural processors. The memory 134 can take any suitable form, including a non-volatile memory and / or RAM. The non-volatile memory may include read only memory (ROM), a hard disk drive (HDD), or a solid state drive (SSD). The memory can store, among other things, an operating system. The RAM is used by the processor for the temporary storage of data. According to an embodiment, an operating system may contain code which, when executed by controller 130, controls operation of the hardware components of power toothbrush device 100. According to an embodiment, connectivity module 138 transmits collected sensor data, and can be any module, device, or means capable of transmitting a wired or wireless signal, including but not limited to a Wi-Fi, Bluetooth, near field communication, and / or cellular module.

[0054] Referring to FIGS. 6A-6B, a close-up view of the resonator 120 and a perspective view of the drivetrain assembly 122 within the handle 112 are shown, respectively. FIG. 6C depicts a top view of an actuator 200 and magnet 202 of the drivetrain assembly 122 along with a crosssection and working principle view of the magnet 202 performing the sweeping motion. FIG. 6D depicts that of the magnet 202 performing the tapping motion, described below. The actuator 200 includes a core 204 and first and second coils 206 and 208, respectively, coupled to the core 204. In this example, the core 204 is a metal U-shaped core and has first arm 210 and second arm 212 which the first and second coils 206 and 208 are wrapped around, respectively. As explained further below, the winding direction of the coils around the core 204 influences the motion made during the phase shifts generated by the coils. In this example, the coils 206 / 208 are wrapped around the respective arms 210 / 212 in opposite winding directions, but it is contemplated that the coils can be wrapped in like winding directions.2025PF00381

[0055] As shown in FIG. 6C, a magnet 202, such as a permanent magnet, is positioned adjacent to the distal ends of the arms 210 / 212 of the core 204 and has a north pole and south pole. The magnet 202 is connected to the brush head shaft 124 via a coupling spring 214 which then transmits the motion of the magnet 202 to the brush head shaft 124. In some embodiments, the drivetrain assembly 122 includes a double resonant mechanism that is driven by the first and second coils 206 / 208. The first and second coils 206 / 208 are driven in parallel by the controller 130 with an alternating voltage (as should be understood by a person of ordinary skill in the art in conjunction with a review of this disclosure). The alternating voltage creates an alternating north and south pole at the distal end of the U-shaped core 204 (i.e., alternating between a north pole at the distal end of the first arm 210 / a south pole at the distal end of the second arm 212 and a south pole at the distal end of the first arm 210 / a north pole at the distal end of the second arm 212). The north and south poles created at the core 204 interact with the north and south poles of the magnet 202, causing the like poles to repel each other and the opposing poles to attract each other. The switching of the attraction and repulsion of the magnet 202 to the core 204 provides an oscillatory rotational motion to the resonator 120 which is transmitted to the brush head shaft 124 via the coupling spring 214 and allows the brush head 114 and cleaning elements (i.e., bristles 116) to perform a first movement pattern (i.e., the sweeping motion). In this embodiment, the coupling spring 214 extends between the first and second arms, as shown in FIG. 6A.

[0056] As described above, cleaning performance can be enhanced by adding an additional degree of freedom to the brush head motion, such as tapping. As described above, the sweeping motion is created by the controller 130 generating and transmitting a voltage to the coils 206 / 208 such that the coils 206 / 208 have an alternating opposing polarity. The coils 206 / 208 can also be driven in a way that they both have the same or a like polarity, alternating between north and south poles at a specified frequency. Referring to FIG. 6D, to induce the tapping motion, the coils 206 / 208 can have the same polarity, alternating between both arms 210 / 212 having a north pole and then a south pole, which interacts with the magnet 202, causing the magnet to be pulled or pushed vertically with respect to the core 204, allowing the brush head 114 and cleaning elements to perform a second movement pattern (i.e., the tapping motion). As described further below, by driving the coils in a certain way, the sweeping and tapping motion of the brush head 114 can happen alone or simultaneously, advantageously providing motion with two degrees of freedom without the need of a second actuator.2025PF00381

[0057] Referring to FIGS. 7A-7B, in the described actuator system, each of the two coils 206 / 208 is driven independently by separate electronic drivers. This configuration enables the introduction of a controllable phase shift between the signals supplied to each coil 206 / 208. The resulting phase shift directly influences the magnetic field generated by the coils, thereby affecting the actuator’s motion characteristics. In this example, when a phase shift of 180° is applied between the coil signals, the actuator exhibits the tapping motion. Conversely, when a phase shift of 0° is applied between the coil signals, the actuator exhibits the sweeping motion, which is equivalent to the behavior observed when both coils are connected together and driven in unison. It should be understood that the specific motion modes associated with the 0° and 180° phase shifts are dependent on the winding direction of the coils and their connection to the electronic drivers. Altering the winding direction and / or the driver connections can reverse the motion modes. In the current embodiment and as illustrated in FIG. 7A, the coils are configured with opposite winding directions, as explained above.

[0058] To create the combined, simultaneous motion of sweeping and tapping, the 0° phase shifted voltage is combined with the 180° phase shifted voltage, with the 0° phase shifted voltage having a different frequency than the 180° phase shifted voltage. If the frequencies are the same, the voltages for one coil will cancel out the other. An exemplary table detailing the logic for the combination of driving signals with the two frequencies based on embodiments is shown in Table 1 below.Table 1: Combination of Sweeping Driving Voltage with Tapping Driving Voltage2025PF00381

[0059] Referring now to FIGS. 8-9, in this example, the controller is configured to drive each coil independently, allowing for precise control over the magnetic field dynamics by generating distinct driving signals for each coil, as exemplified in Table 1. It should be appreciated that while some embodiments combine signals of two frequencies, other embodiments, such as the embodiment depicted in FIG. 11, drive the four coils independently using a single frequency. Referring to FIG. 9, the driving mechanism can be implemented using a dual arbitrary waveform generator. The generator produces synchronized signals to the first and second coils 206 / 208, as shown in FIG 7B. The synchronization of the signals allows for the maintained coordinated control over the actuator’s motion. The generated signals are then amplified and transmitted to the respective coils.

[0060] In accordance with an alternative embodiment, instead of using analog amplifiers as shown in FIG. 9, a full bridge for each coil can be used, as shown in FIG. 10. In this configuration, a control unit 1000 can generate digital signals corresponding to the desired driving voltage profiles shown in FIG. 8 and Table 1. The electronic drivers act as an interface between the control unit and the switches Sil, S12, S13, S14, S21, S22, S23, and S24. In accordance with an embodiment, the switches are implemented using MOSFETs. To operate both high-side and low-side switches effectively, electronics may be needed to generate appropriate gate-source voltages to ensure reliable switching performance and accurate signal delivery to each coil.

[0061] The operational effect of the power toothbrush device described herein is that it can provide improved cleansing performance at critical areas of the mouth by driving the bristles of the toothbrush in a vertical periodic motion that is parallel to the direction of the bristles or an axis of alignment of the bristles. The tapping motion: (i) achieves deeper reach in gum pockets to remove subgingival plaque, (ii) achieves higher peak forces at surfaces which improve plaque and / or stain removal, (iii) prevents pinning of bristle tufts which improves plaque removal by restoring beneficial tuft sweeping behavior, (iv) achieves more resilience to variables of use like toothbrush placement, toothbrush angle, and toothbrush pressure, and (v) provides new options for experiential modes for the consumer.

[0062] In some embodiments, an alternative variation approach is employed that introduces a dual-actuator configuration that enables the simultaneous and independent generation of two distinct movement patterns as demonstrated by FIG. 11. By employing two separate actuator2025PF00381assemblies instead of the single actuator described above, the drivetrain assembly 122 allows for independent control of the sweeping and tapping motions and a more efficient transmission of the tapping motion. This can be achieved through the controller 130, which generates and transmits distinct driving signals to each pair of coils. This independence enables precise tuning of the amplitude and frequency of each motion, enhancing the cleaning performance and adaptability of the device. This embodiment has the same function and construction as the above embodiments unless otherwise indicated. As such, certain reference numerals are intentionally reused below.

[0063] Referring to FIG. 11, the alternative H-shaped (i.e., first U-shaped core 204A and second U-shaped core 204B connected or integrally formed together) configuration is shown, which enables the implementation of independent yet simultaneous sweeping and tapping motions in the oral cleaning device 100. This configuration utilizes a double-actuator system, enhancing the cleaning performance and adaptability of the device.

[0064] The H-shaped core 203 is a ferromagnetic assembly that incorporates two actuator assemblies: a first actuator assembly designed to produce and transmit a sweeping motion and a second actuator assembly configured to generate and transmit a tapping motion. The H-shaped structure 203 includes four coils: first coil 206, second coil 208, third coil 205, and fourth coil 207. The coils 206, 208, 205, and 207 are wound around the arms of the H-shaped structure and extend parallel to the central axis of the oral cleaning device. See above for a discussion on the winding direction of the coils.

[0065] A first and second resonator 120 / 121 is also included and includes two magnets (first (rotational) magnet 202 and second (tapping) magnet 209) positioned adjacent the free ends of the respective pairs of coils, with each pair of coils positioned on opposite pairs of arms 204A’ and 204B’ of the H-shaped core 203 as shown.

[0066] The first actuator assembly 200-1 includes the first coil 206, the second coil 208, and a rotational magnet 202. The rotational magnet 202 is positioned adjacent to the free ends of the first and second coils. When alternating magnetic fields are generated by the first and second coils, the poles of the rotational magnet 202 interact with these fields, producing a rotational sweeping motion. This rotational sweeping motion is transmitted to the brush head shaft via the coupling spring 214, enabling the sweeping motion of the brush head.2025PF00381

[0067] The second actuator assembly 200-2 includes the third coil 205, the fourth coil 207, and a tapping magnet 209. The tapping magnet 209 is positioned adjacent to the free ends of the third and fourth coils 205, 207. When the third and fourth coils are driven with synchronized polarity, the tapping magnet 209 is displaced linearly along an axis parallel to the z-axis of the device. This linear motion is directly transmitted to the brush head shaft, enabling the tapping motion of the brush head.

[0068] The coupling spring 214 in the first actuator assembly 200-1 facilitates the transmission of rotational motion generated by the first actuator assembly to the brush head shaft 124. Conversely, the second actuator assembly 200-2 establishes a direct connection between the tapping magnet 209 and the brush head shaft 124, enabling accurate and efficient generation of the tapping motion. As such, in some embodiments, the free ends of the first pair of coils 206 / 208 are directed away from the brush head 114 and the free ends of the second pair of coils 205 / 207 are directed towards brush head 114.

[0069] The independent control of the driving signals to the first and second actuator assemblies allows the sweeping and tapping motions to be performed simultaneously or separately. This dual-actuator configuration provides enhanced flexibility in operation, enabling the device to adapt to various cleaning requirements. For example, the sweeping motion can be used for broad surface cleaning, while the tapping motion can target interproximal areas or gum pockets. Additionally, both motions can be combined to achieve improved cleaning performance in challenging areas.

[0070] While it is described that one actuator assembly performs the sweeping motion while the other actuator assembly performs the tapping motion, it is additionally contemplated that both actuator assemblies perform sweeping or both actuator assemblies perform tapping simultaneously. This could provide additional power to the oral cleaning device for hard to reach areas.

[0071] In one embodiment, the drivetrain assembly may utilize first and second U-shaped structures constructed from a high-permeability ferromagnetic material, such as silicon steel, to enhance magnetic flux efficiency. Alternatively, these structures could be made from a composite material with reduced eddy current losses, such as ferrite. The first and second pairs of coils may be wound using copper wire with varying gauges to optimize current flow and heat dissipation, or alternatively, aluminum wire could be used for weight reduction. The coupling spring may be2025PF00381implemented as a helical spring, a torsion spring, or a leaf spring, depending on the desired stiffness and motion transmission characteristics. In embodiments, the first and second magnets may be constructed from neodymium for high magnetic strength, or from ceramic materials for cost efficiency. The controller may be configured to generate driving signals with different waveforms, such as sinusoidal, square, or triangular waves, to achieve specific movement patterns. Additionally, the controller could include adaptive algorithms to dynamically adjust the driving signals based on feedback from sensors monitoring motion of the brush head. The drivetrain assembly may also be configured such that the first and second U-shaped structures are combined to form an H-shaped structure, or they may be separate components to allow modular assembly. Furthermore, the second actuator assembly could be designed to generate a tapping motion along an axis perpendicular to the rotational axis, or alternatively, it could produce a secondary rotational motion at a different frequency to enhance cleaning performance. The brush head shaft may be aligned coaxially with the central axis of the oral cleaning device or offset to accommodate specific ergonomic designs.

[0072] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0073] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0074] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified.

[0075] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items.2025PF00381Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”

[0076] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified.

[0077] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively.

[0078] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

[0079] While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performing the function and / or obtaining the results and / or one or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and / or configurations will depend upon the specific application or applications for which the inventive teachings is / are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine2025PF00381experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods, if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

Claims

2025PF00381ClaimsWhat is claimed is:

1. A drivetrain assembly (122) of an oral cleaning device (100), the drivetrain assembly (122) comprising:a first actuator assembly (200-1) comprising:a first U-shaped core (204A) having a first pair of arms (204A’) with a first pair of coils (206 / 208);a first resonator (120) with a first magnet (202) positioned adjacent free ends of the first pair of coils (206 / 208); anda coupling spring (214) connected to the first magnet (202) and a brush head shaft (124), wherein the coupling spring (214) transmits a first generated motion to a brush head (114) of the oral cleaning device (100); anda second actuator assembly (200-2) comprising:a second U-shaped core (204B) having a second pair of arms (204B’) with a second pair of coils (205 / 207); anda second resonator (121) with a second magnet (209) positioned adjacent free ends of the second pair of coils (205 / 207), wherein the second resonator (121) and the second magnet (209) are directly connected to the brush head shaft (124); anda controller (130) configured to:generate and transmit to the first pair of coils (206 / 208) first driving signals that interact with north and south poles of the first magnet (202) to generate a first movement pattern comprising the first generated motion; andgenerate and transmit to the second pair of coils (205 / 207) second driving signals that interact with north and south poles of the second magnet (209) to generate a second movement pattern simultaneously as the first movement pattern.

2. The drivetrain assembly (122) of claim 1, wherein the first U-shaped core (204A) is integral with the second U-shaped core (204B).

3. The drivetrain assembly (122) of claim 1, wherein each coil of the first pair of coils (206 / 208) is wrapped around an arm of the first pair of arms (204A’), each coil (206 / 208) extends2025PF00381parallel to a central axis of the oral cleaning device (100), and the free ends of the first pair of coils (206 / 208) are directed away from the brush head (114).

4. The drivetrain assembly (122) of claim 3, wherein each coil of the second pair of coils (205 / 207) is wrapped around an arm of the second pair of arms (204B’), each coil (205 / 207) extends parallel to a central axis of the oral cleaning device (100), and the free ends of the second pair of coils (205 / 207) are directed toward the brush head (114).

5. The drivetrain assembly (122) of claim 1, wherein the coupling spring (214) extends parallel to a central axis of the oral cleaning device (100) alongside the first (204A) and second (204B) U-shaped cores.

6. The drivetrain assembly (122) of claim 1, wherein the controller (130) is configured to generate and transmit to the second pair of coils (205 / 207) third driving signals that interact with the north and south poles of the second magnet (209) to generate the first movement pattern.

7. The drivetrain assembly (122) of claim 6, wherein the third driving signals are transmitted simultaneously as the first driving signals.

8. The drivetrain assembly (122) of claim 7, wherein the controller (130) is configured to generate and transmit the first driving signals set to a first frequency, and at the same time generate and transmit the third driving signals set to a second frequency, different than the first frequency.

9. The drivetrain assembly (122) of claim 1, wherein the first movement pattern comprises rotating the first magnet (202) and the brush head (114) about a central axis of the oral cleaning device (100).

10. The drivetrain assembly (122) of claim 9, wherein the second movement pattern is the same as the first movement pattern.

11. The drivetrain assembly (122) of claim 9, wherein the second movement pattern comprises moving the second magnet (209) and the brush head (114) along another axis of the oral cleaning device (100).

12. The drivetrain assembly of claim 11, wherein the another axis is substantially parallel to an axis of alignment of bristles (116) of the brush head (114).2025PF0038113. An oral cleaning device (100), comprising:a body portion (102);a brush head (114) removably coupled to the body portion (102) and comprising a set of cleaning bristles (116); anda drivetrain assembly (122) within the body portion (102), the drivetrain assembly (122) comprising:a first actuator assembly (200-1) comprising:a first U-shaped core (204A) having a first pair of arms (204A’) with a first pair of coils (206 / 208);a first resonator (120) with a first magnet (202) positioned adjacent free ends of the first pair of coils (206 / 208); anda coupling spring (214) connected to the first magnet (202) and a brush head shaft (124), wherein the coupling spring (214) transmits a first generated motion to a brush head (114) of the oral cleaning device (100); anda second actuator assembly (200-2) comprising:a second U-shaped core (204B) having a second pair of arms (204B’) with a second pair of coils (205 / 207); anda second resonator (121) with a second magnet (209) positioned adjacent free ends of the second pair of coils (205 / 207), wherein the second resonator (121) and the second magnet (209) are directly connected to the brush head shaft (124); anda controller (130) configured togenerate and transmit first driving signals to the first pair of coils (206 / 208) that interact with north and south poles of the first magnet (202) to generate a first movement pattern comprising the first generated motion; andgenerate and transmit second driving signals to the second pair of coils (205 / 207) that interact with north and south poles of the second magnet (209) to generate a second movement pattern simultaneously as the first movement pattern.

14. The oral cleaning device of claim 13, wherein the first U-shaped core (204 A) is integral with the second U-shaped core (204B).

15. The oral cleaning device (100) of claim 13, wherein the first movement pattern comprises rotating the first magnet (202) and the brush head (114) about a central axis of the oral cleaning2025PF00381device (100); and wherein the second movement pattern is the same as the first movement pattern or the second movement pattern comprises moving the second magnet (209) and the brush head (114) along another axis of the oral cleaning device (100).

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